Although normal personality traits change gradually with age, personality disorders have been reported to remit rapidly and completely in little more than 10 years. Such a benign prognosis is surprising and may be due in part to the combined use of categorical diagnoses, seriously ill patients, and longitudinal designs in the existing literature. This study examines, for the first time, the development of personality pathology across a life span by means of dimensional models, represented by the Dimensional Assessment of Personality Pathology-Basic Questionnaire and the Personality Inventory for Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. We draw upon a cross-sectional design and four large clinical and community samples to avoid previous biases. We found that personality pathology declined by around 0.5 SD overall from age 20 to 60, though with noticeable differences between domains: Dissocial behavior and antagonism decreased by between two thirds and 1 SD; compulsivity increased at the same rate; disinhibition, negative affect, and psychoticism dropped by 0.5 SD; and detachment remained stable or rose slightly. In short, the changes in many clinically important traits are modest, occur at a slow pace, and roughly parallel the maturation effect found for normal personality traits. The resulting picture of personality disorder development is not as optimistic as previous studies would have us believe.